The latest hot product from the athletic shoe industry is the so-called toning shoe -- a fancy sneaker with an unstable sole that's supposed to make your leg muscles work harder during everyday activities.
Shoe companies say that toning shoes can sculpt your legs and reduce the girth of your backside while you walk, as in a Skechers ad: "Get in shape without setting foot in a gym." But at least two new studies suggest such claims are untrue.
Skechers and companies like Reebok and MBT are all selling versions of toning shoes, from $100 a pair to as much as $245 a pair.
Outside her office in Boston this week, Carin Willis was wearing her MBTs, which have big, thick, curved soles that look like big rubber rockers. "They're very heavy. They're very ugly," she says.
Maybe so -- but she says they have helped her sore back.
"I followed the hype of great for your legs, great for all that," Willis says. "Do I think they've resculpted my legs? No. But I do think it has helped with my back and my posture."
Toning shoes represent the fastest-growing segment of the shoe industry. In the Skechers store in downtown Boston, a manager says the shoes are flying out of his store -- even if customer Muhammad Jaffa seems skeptical. "Yeah, the way they look, I don't like them," Jaffa says.
"They claim that if you walk in them they tone your muscles -- they make your muscles stronger," the manager says.
"I have no clue about that. You have some research about that?"
In fact, there is research; it just doesn't all agree. The latest two studies come from the American Council on Exercise. The nonprofit group compared the benefits of toning shoes from Skechers, Reebok and MBT with ordinary running shoes.
"Both studies found that there was no significant difference between any of the toning shoes and the standard running shoe," says ACE's Todd Galati. Bottom line, says Galati, is that claims that toning shoes help people burn extra calories, improve muscle tone and build strength are bunk.
"These shoes are not a magic pill. It is the walking that will make a difference in your life. Not the shoe," he says.
But that's not the way Skechers sees it.
"Well, first of all, I would say that the study that they conducted is deeply flawed," says Leonard Armato, president of Skechers Fitness Group. He says the ACE studies are too limited. He says they're contradicted by what he calls "more than a dozen larger and more rigorous studies" -- and by customer response.
"Skechers has received 12,000 unsolicited positive reviews of Shape-ups," Armato says. "And many of these people insist that the benefits they have received have literally transformed their lives for the better."
But ACE stands by its studies, pointing out that they were conducted by independent researchers at the University of Wisconsin.
Galati of ACE does concede that while toning shoes aren't magic, they might motivate people to walk and exercise more -- and that can only be a good thing.